Our IT department sent us "certificates file(s) in PEM format and PKCS#12 format to be used by clients".
They gave us the following instructions:
The php-mysqli library only requires you to set the CA file for the mysqli connection object using the
Example (db_connect_mysqli.php) (modify the user, password, server, and port)
mysqli_ssl_set($con,NULL,NULL,"[.pem CERT NAME]",NULL,NULL);
die("Connect Error: " . mysqli_connect_error());
$query = "select * from information_schema.session_status where variable_name = 'ssl_cipher'";
$res = mysqli_query($con ,$query);
Run: php -f db_connect_mysqli.php
 => SSL_CIPHER
[VARIABLE_NAME] => SSL_CIPHER
 => DHE-RSA-AES256-SHA
[VARIABLE_VALUE] => DHE-RSA-AES256-SHA
As you might gather from all of the quoting, I'm not entirely clear on what this means in terms of what I need to to do our server/Moodle. There appears to be a certificate I need to install and...some part of the Moodle core to alter?
Any suggestions on where to go from here would be much appreciated.